scholarly journals Cytotoxic Activity of Dendritic Cells as a Possible Mechanism of Negative Regulation of T Lymphocytes in Pulmonary Tuberculosis

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ludmila V. Sakhno ◽  
Marina A. Tikhonova ◽  
Tamara V. Tyrinova ◽  
Olga Yu. Leplina ◽  
Ekaterina Ya. Shevela ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Pulmonary Tuberculosis ◽  
Cell Apoptosis ◽  
Mixed Lymphocyte Culture ◽  
Lymphocyte Culture ◽  
Blood Monocytes ◽  
General Group ◽  
T Cell Apoptosis

The PD-1/B7-H1-mediated induction of T cell apoptosis/anergy as a possible mechanism of immune response failure was studied in 76 patients with pulmonary tuberculosis (TB) with normal and low-proliferative response to antigens ofM. tuberculosis(purified protein derivative (PPD)). It was revealed that dendritic cells (DCs), generatedin vitrofrom patient blood monocytes with GM-CSF + IFN-α, were characterized by increased B7-H1 expression, upproduction of IL-10, and reducing of allostimulatory activity in mixed lymphocyte culture (MLC). Moreover, DCs of patients with TB were able to enhance T cell apoptosis and to block T-cell division in MLC. It was shown that neutralizing anti-PD1 antibodies significantly decreased the proapoptogenic/tolerogenic effect of DCs. Correlation analysis revealed a direct relationship between IL-10 production and level of B7-H1 expression in the general group of investigated patients. It was demonstrated that generation of healthy donor DCs in the presence of IL-10 led to an increase in the number of DCs-expressed B7-H1 molecule, DC proapoptogenic activity, and a decrease in their allostimulatory activity. Obviously, the revealed phenomenon of the PD-1/B7-H1-mediated pro-apoptogenic activity of DCs is clinically significant since the cytotoxic/tolerogenic potential of DCs is more pronounced in patients with PPD anergy.

Lack of control of T cell apoptosis under HAART. Influence of therapy regimen in vivo and in vitro

AIDS ◽  
2002 ◽  
Vol 16 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Luzia Maria de Oliveira Pinto ◽  
Hervé Lecoeur ◽  
Eric Ledru ◽  
Christophe Rapp ◽  
Olivier Patey ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Apoptosis ◽  
Therapy Regimen ◽  
T Cell Apoptosis ◽  
Lack Of Control

T CELL APOPTOSIS INDUCED BY LIVER B220+ DENDRITIC CELLS: A MECHNISTIC INSIGHT

2004 ◽  
Vol 78 ◽  
pp. 548-549
Author(s):  
L Lu ◽  
X Y. Liang ◽  
L Wang ◽  
J J. Fung ◽  
S Qian
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Cell Apoptosis ◽  
T Cell Apoptosis

scholarly journals Impairments of Antigen-Presenting Cells in Pulmonary Tuberculosis

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ludmila V. Sakhno ◽  
Ekaterina Ya. Shevela ◽  
Marina A. Tikhonova ◽  
Sergey D. Nikonov ◽  
Alexandr A. Ostanin ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Pulmonary Tuberculosis ◽  
Peripheral Blood ◽  
Antigen Presenting Cells ◽  
T Cell Response ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Gm Csf ◽  
Antigen Presenting

The phenotype and functional properties of antigen-presenting cells (APC), that is, circulating monocytes and generatedin vitromacrophages and dendritic cells, were investigated in the patients with pulmonary tuberculosis (TB) differing in lymphocyte reactivity toM. tuberculosisantigens (PPD-reactive versus PPD-anergic patients). We revealed the distinct impairments in patient APC functions. For example, the monocyte dysfunctions were displayed by low CD86 and HLA-DR expression, 2-fold increase in CD14+CD16+expression, the high numbers of IL-10-producing cells, and enhanced IL-10 and IL-6 production upon LPS-stimulation. The macrophages which werein vitrogenerated from peripheral blood monocytes under GM-CSF were characterized by Th1/Th2-balance shifting (downproduction of IFN-γcoupled with upproduction of IL-10) and by reducing of allostimulatory activity in mixed lymphocyte culture. The dendritic cells (generatedin vitrofrom peripheral blood monocytes upon GM-CSF + IFN-α) were characterized by impaired maturation/activation, a lower level of IFN-γproduction in conjunction with an enhanced capacity to produce IL-10 and IL-6, and a profound reduction of allostimulatory activity. The APC dysfunctions were found to be most prominent in PPD-anergic patients. The possible role of APC impairments in reducing the antigen-specific T-cell response toM. tuberculosiswas discussed.

scholarly journals Locally produced C5a binds to T cell–expressed C5aR to enhance effector T-cell expansion by limiting antigen-induced apoptosis

Blood ◽  
2008 ◽  
Vol 112 (5) ◽  
pp. 1759-1766 ◽  
Author(s):  
Peter N. Lalli ◽  
Michael G. Strainic ◽  
Min Yang ◽  
Feng Lin ◽  
M. Edward Medof ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Apoptosis ◽  
Cell Expansion ◽  
Immune Cell ◽  
Regulatory Protein ◽  
T Cell Apoptosis ◽  
T Cell Expansion

Abstract Our recent studies have shown that immune cell–produced complement provides costimulatory and survival signals to naive CD4+ T cells. Whether these signals are similarly required during effector cell expansion and what molecular pathways link locally produced complement to T-cell survival were not clarified. To address this, we stimulated monoclonal and polyclonal T cells in vitro and in vivo with antigen-presenting cells (APCs) deficient in the complement regulatory protein, decay accelerating factor (DAF), and/or the complement component C3. We found that T-cell expansion induced by DAF-deficient APCs was augmented with diminished T-cell apoptosis, whereas T-cell expansion induced by C3−/− APCs was reduced because of enhanced T-cell apoptosis. These effects were traced to locally produced C5a, which through binding to T cell–expressed C5aR, enhanced expression of Bcl-2 and prevented Fas up-regulation. The results show that C5aR signal transduction in T cells is important to allow optimal T-cell expansion, as well as to maintain naive cell viability, and does so by suppressing programmed cell death.

scholarly journals High-Affinity Anti-VISTA Antibody Protects against Sepsis by Inhibition of T Lymphocyte Apoptosis and Suppression of the Inflammatory Response

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tianzhu Tao ◽  
Lulong Bo ◽  
Teng Li ◽  
Longbao Shi ◽  
Hui Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Checkpoint ◽  
Cell Apoptosis ◽  
Expression Profiles ◽  
Cytokine Expression ◽  
Lymphocyte Apoptosis ◽  
T Cell Apoptosis ◽  
High Affinity

Background. B7 family members and ligands have been identified as critical checkpoints in orchestrating the immune response during sepsis. V-domain Ig suppressor of T cell activation (VISTA) is a new inhibitory immune checkpoint involved in restraining T cell response. Previous studies demonstrated that VISTA engagement on T cells and myeloid cells could transmit inhibitory signals, resulting in reduced activation and function. The current study was designed to determine the potential therapeutic effects of a high-affinity anti-VISTA antibody (clone MH5A) in a murine model of sepsis. Methods. Polymicrobial sepsis was induced in male C57BL/6 mice via cecal ligation and puncture. Expression profiles of VISTA on T lymphocytes and macrophage were examined at 24 and 72 h postsurgery. The effects of anti-VISTA mAb on the 7-day survival, lymphocyte apoptosis, cytokine expression, bacterial burden, and vital organ damage were determined. Furthermore, the effects of anti-VISTA mAb on CD3+ T cell apoptosis and macrophage activation were determined in vitro. Results. VISTA was substantially expressed on T cells and macrophages in sham-operated mice; septic peritonitis did not induce significant changes in the expression profiles. Treatment with MH5A improved the survival of septic mice, accompanied by reduced lymphocyte apoptosis, decreased cytokine expression, and enhanced bacterial clearance. Engagement of VISTA receptor with MH5A mitigated CD3+ T cell apoptosis cultured from CLP mice and suppressed LPS-induced cytokine production by macrophage in vitro. Conclusion. The present study identified VISTA as a novel immune checkpoint in the regulation of T cell and macrophage response during sepsis. Modulation of the VISTA pathway might offer a promising opportunity in the immunotherapy for sepsis.

Targeting Lymphocyte Activation Gene 3 to Reverse T-Lymphocyte Dysfunction and Improve Survival in Murine Polymicrobial Sepsis

2020 ◽  
Vol 222 (6) ◽  
pp. 1051-1061
Author(s):  
Jing-sheng Lou ◽  
Jia-feng Wang ◽  
Miao-miao Fei ◽  
Yan Zhang ◽  
Jun Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Apoptosis ◽  
Interleukin 2 ◽  
Lymphocyte Activation ◽  
Interferon Γ ◽  
T Cell Apoptosis ◽  
Cytokine Levels ◽  
Lymphocyte Activation Gene

Abstract Background Lymphocyte activation gene 3 (LAG-3) is one of the immune checkpoint molecules, negatively regulating the T-cell reactions. The present study investigated the role of LAG-3 in sepsis-induced T-lymphocyte disability. Methods Mice sepsis was induced by cecal ligation and puncture (CLP). LAG-3 expression on some immune cells were detected 24 hours after CLP. LAG-3 knockout and anti–LAG-3 antibody were applied to investigate the effects on the survival, bacterial clearance. Cytokine levels, T-cell counts, and the presence of apoptosis (in blood, spleen, and thymus) were also determined. In vitro T-cell apoptosis, interferon γ secretion, and proliferation were measured. The expression of interleukin 2 receptor on T cells was also determined after CLP. Results LAG-3 was up-regulated on CD4+/CD8+ T, CD19+ B, natural killer, CD4+CD25+ regulatory T cells and dendritic cells. Both LAG-3 knockout and anti–LAG-3 antibody had a positive effect on survival and on blood or peritoneal bacterial clearance in mice undergoing CLP. Cytokine levels and T-cell apoptosis decreased in anti–LAG-3 antibody–treated mice. Induced T-cell apoptosis decreased, whereas interferon γ secretion and proliferation were improved by anti–LAG-3 antibody in vitro. Interleukin 2 receptor was up-regulated on T cells in both wild-type and LAG-3–knockout mice undergoing CLP. Conclusions LAG-3 knockout or anti–LAG-3 antibody blockade protected mice undergoing CLP from sepsis-associated immunodysfunction and may be a new target for the treatment.

scholarly journals Ineffective Cellular Immune Response Associated with T-Cell Apoptosis in Susceptible Mycobacterium bovisBCG-Infected Mice

2000 ◽  
Vol 68 (7) ◽  
pp. 4264-4273 ◽  
Author(s):  
Laurent Kremer ◽  
Jérôme Estaquier ◽  
Isabelle Wolowczuk ◽  
Franck Biet ◽  
Jean-Claude Ameisen ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Proliferation ◽  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Cell Apoptosis ◽  
T Cell Proliferation ◽  
T Cell Apoptosis ◽  
Tnf Α

ABSTRACT It has previously been reported that inhibition of delayed-type hypersensitivity-mediating functions of T cells during mycobacterial infection in mice is haplotype dependent. In the present study, we show that Mycobacterium bovis BCG infection induced, in susceptible C57BL/6 and BALB/c mice but not in resistant C3H/HeJ and DBA/2 mice, an important splenomegaly. An in vitro defect in T-cell proliferation in response to T-cell receptor (TCR) stimulation with mitogens or anti-CD3 antibodies was associated with enhanced levels of CD4+ and CD8+ T-cell apoptosis in susceptible but not in resistant mice 2 weeks after infection. Further investigations of C57BL/6 and C3H/HeJ mice revealed that in vivo splenomegaly was associated with destruction of the lymphoid tissue architecture, liver cellular infiltrates, and increased numbers of apoptotic cells in both spleen and liver tissue sections. Infection of C57BL/6 mice but not of C3H/HeJ mice induced massive production of tumor necrosis factor alpha (TNF-α) in serum, as well as an increase in Fas and Fas ligand (FasL) expression in T cells. In vitro addition of neutralizing anti-TNF-α antibodies led to a significant reduction in CD3-induced T-cell apoptosis of both CD4+ and CD8+ T cells of C57BL/6 mice, while the blockade of Fas-FasL interactions reduced apoptosis only in CD4+ but not in CD8+ T cells. Together, these results suggest that TNF-α and Fas-FasL interactions play a role in the activation-induced cell death (AICD) process associated with a defect in T-cell proliferation of the susceptible C57BL/6 mice. T-cell death by apoptosis may represent one of the important components of the ineffective immune response against mycobacterium-induced immunopathology in susceptible hosts.

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